This invention relates to a plate-type recuperative heat exchanger. In this heat exchanger hot exhaust gases are directed through a first plurality of passageways formed by the plate in the core of the heat exchanger. Supply air is directed through a second set of passageways defined by the plates of the heat exchanger to recover heat from the exhaust gases. The supply air is directed through the core of the heat exchanger in a direction that is substantially opposite to the direction of flow of the exhaust gases. This recuperative heat exchanger is designed to be used for high temperature applications where the temperature of the exhaust gases can be as high as 1500.degree. F.
In the past recuperative heat exchangers have been used to recover energy from exhaust gases so that this energy can be reused in other processes. Platetype heat exchangers are commonly used for achieving an indirect heat transfer between two circulating fluids at different temperatures. These heat exchangers generally consist of a plurality of spaced parallel plates welded or otherwise attached between two end plates to define parallel passages. Manifolds are attached to the ends of the passages to direct each fluid to alternate passages so that each plate forms a heat conducting interface between the two fluids. However, there is difficulty when utilizing such heat exchangers for high temperature applications. The stresses incurred by the expansion and contraction of the components of the heat exchanger during use can result in a failure of the recuperative heat exchanger. Because of structural limitations, this type of heat exchanger unit is not suitable for high temperature installations. Accordingly, a lot of heat energy was wasted because it was not possible to use such heat exchangers at the areas of high temperature where the most energy can be recovered. Accordingly, it is an object of the present invention to provide a recuperative-type heat exchanger to be used in high temperature applications.
It is a further object of the invention to provide a recuperative-type heat exchanger where the plates that form the core of the heat exchanger are free to expand and contract during the operation of the heat exchanger.
It is an object of the invention to provide a recuperative heat exchanger having a high efficiency.
Other objects and advantages of the invention will be apparent from the following detailed description of the invention.